Heating · Idaho
How Much Does It Cost to Run an Electric Water Heater in Idaho?
The short answer
In Idaho, an electric water heater drawing 4,500W costs about $0.62 per hour — roughly $56.38 a month if it runs 3 hours a day.
That’s based on Idaho’s average residential rate of 13.7¢/kWh (EIA, July 2026), 25% below the US average.
Source: U.S. EIA, July 2026 data · Updated
Electric Water Heater cost by daily use in Idaho
| Daily use | kWh/month | Per day | Per month | Per year |
|---|---|---|---|---|
| 1 hour/day | 136.9 | $0.62 | $18.79 | $226 |
| 2 hours/day | 273.8 | $1.24 | $37.59 | $451 |
| 4 hours/day | 547.6 | $2.47 | $75.18 | $902 |
| 8 hours/day | 1,095.1 | $4.94 | $150 | $1,804 |
| 12 hours/day | 1,642.7 | $7.41 | $226 | $2,706 |
| 24 hours/day | 3,285.4 | $14.83 | $451 | $5,412 |
Idaho vs other states
At typical use, an electric water heater costs $677 a year in Idaho — $1,689 less than in Hawaii and $49.77 more than in Louisiana.
Idaho has the 6th-cheapest residential electricity of the 50 states and DC. Idaho electricity rates · all states ranked
Electricity price trend in Idaho
13.7¢/kWh in July 2026 — ▲ +11.8% from a year earlier.
How to lower the cost of running an electric water heater
Electric tank water heaters keep 40–80 gallons of water hot around the clock, switching their heating elements on whenever you use hot water or the tank cools down. The elements are typically 4,500W, and total run time for a family is roughly 2–4 hours a day, which is why water heating is often the second-biggest line on an all-electric home's bill. Heat pump water heaters do the same job with 2–3 times less electricity.
- Set the tank to 120°F (49°C) — many ship at 140°F, which wastes energy.
- Insulate the first few feet of hot water pipe and fix dripping hot taps.
- Consider a heat pump water heater when your tank needs replacing — they use about a third of the electricity.
Questions
Frequently asked questions
How much does it cost to run an electric water heater for 24 hours in Idaho?
Running a 4,500W electric water heater for 24 hours uses about 108 kWh, which costs about $14.83 at Idaho’s average rate of 13.7¢/kWh.
How many kWh does an electric water heater use per month?
At 3 hours a day, a typical electric water heater uses about 411 kWh a month. In Idaho that costs $56.38.
Is it expensive to run an electric water heater in Idaho?
Idaho has the 6th-cheapest residential electricity of the 50 states and DC at 13.7¢/kWh — one of the cheapest. Running an electric water heater here costs about $677 a year at typical use, compared with $902 at the national average rate.
What is the electricity rate in Idaho right now?
The average residential electricity rate in Idaho was 13.7¢ per kWh in July 2026, according to the latest EIA data — up 11.8% from a year earlier.
How many hours a day does an electric water heater run?
For a typical household, about 2–4 hours a day in total, spread across showers, laundry and dishes, plus short reheats to make up for standby heat loss.
Electric Water Heater costs in nearby states
Other appliances in Idaho
Cheapest and priciest states
Sources & method
- Electricity rates: U.S. Energy Information Administration, Electric Power Monthly — average residential retail price, July 2026 (latest available). Retrieved .
- CO₂: EIA State Electricity Profiles, 2024 emissions rate of in-state power generation.
- Default usage for electric water heater: 3 hours a day. Typical power 4,500W.
- Formulas, duty cycles and limitations: methodology. Data download: open data (CC BY 4.0).